I just received both my L-0 back plate (flat surface) and my ER 40 collet chuck. The back plate O.D. is 8". The ER-40 collet chuck O.D. is 132 mm (5.196) with a register of 100 mm. I am going to machine a register on the back plate to fit into the collet chuck. So, should I machine the backplate O.D. to 132 mm so it's the same O.D. of the collet chuck? Thks